Mike, did you ever get an answer as to what needs to be put into the Wind velocity winter/summer (MPH) field? Or where that data is found/gathered? Thanks for the video's man.
Thank you for this video. I am trying to get a load calculation for a tricky house, very fancy one and the results look a little bit scary to me. I went through every single detail. I took measurements of the windows, doors, ceiling heights, Floor dimensions, etc and I am still very hesitant about the results. I tried to call them to ask them questions, but they direct you to the email and that, to me, is bad, because there should be more customer support to answer some questions in order to familiarize with the software. When they say HVAC System, are they referring to the system already installed or the one that you are going to install?
I have not had great success with their tech-support (they essentially ignore me), however I'm guessing because they're a software company they may not know / understand all the details of Manual-J and so they probably try to field questions as some of them may be better directed to people / trainers who have a better understanding of Manual-J... It is not uncommon when used to using rules of thumbs for sizing vs. using Manual-J to be uncomfortable with results. Sorry for the delayed reply. I did not see your comment earlier.
I mean without more details on your project it's hard to say. If the inputs are correct, then I do trust the loads that come out of CoolCalc, if that's the question.
Cool-Calc is Manual-J 8 compliant, so it uses values that are found in that edition of Manual-J. I'm not sure that it goes up to R-60 for attics, but R-40 on walls may be able to be accomplished when modeling with exterior insulation + cavity insulation.
@@mhoush I believe Wrightsoft allows you to enter actual R and U values and is also MJ-8 compliant. Frankly, in this age it'd be silly to not allow it.
This from Cool Calc: You have to change the wall type in order to get higher r-value options. For example, a 2x4 wall is going to be limited to R-15 due to the amount of insulation you can fit in a 3.5" cavity, but if you change it to a 2x6 wall, it allows up to r-21. Then you can add additional board insulation on top of that to achieve higher r-values. Getting the r-value close is more important than matching the exact construction type. I believe the highest wall r-value in the Manual J tables is achieved by selecting "Insulated concrete forms", which will get you to about r-36. We allow custom u-values to be entered for windows so that should not be a problem. If you select "ceiling under attic" you can enter r-values up to R-56. The R-33 limit you were seeing was probably on a vaulted open beam ceiling. Our next release will allow custom r-values to be entered, but you will most likely need to make a manual adjustment on your report to account for the difference between R-36 and R-42 walls as well as R-56 to R-62 ceilings. I think you will find that when homes become that efficient the cooling/heating loads are so low that the r-value adjustments are going to be minimal. We can assist with those adjustments if you send us your final report. Best Regards Bill
